Wall mounted electrical boxes are commonly used in the building industry for electrical power outlets, light switches and the like. The electrical boxes can have various tabs or arms for attaching the box to the wall. Many variations exist with some designs being more effective than others.
One type of electrical box includes two pivotal arms that attach to the wall. The arms are often mounted at opposite corners of the box for supporting the sides of the box. An electrical wiring device is mounted within the box by threading screws within a base formed in the box. The pivotal arms can exhibit several problems when positioning the box in an opening in a wall or ceiling. The box can rock from side to side as a result of the positioning of the pivoting arms and the shape and dimension of the opening in the wall. The rocking motion can be eliminated by the shape of the opening which must typically be modified during installation of the box, thereby increasing the labor for the installer.
Various designs and shapes of electrical boxes have been proposed that include a pivoting arm. One example is disclosed in U.S. Pat. No. 6,170,685 to Currier, which discloses a folding electrical outlet box. The top and bottom walls of the box include a tunnel that has an outwardly open slot. A screw is threaded into the tunnel and into a rotating clip. The friction between the screw and clip causes the screw to rotate until some resistance is met. Continued rotation of the screw causes the clip to slide in the slot to secure the box to the wall.
Another electrical box having securing arms is disclosed in U.S. Pat. No. 5,434,359 to Schell. The electrical box has mounting surfaces or contacting points, a pair of bosses and a pair of securing arms. The contacting points are spaced apart along the top and bottom walls and are coplanar with the bosses and arms. The contacting points extend from the top and bottom surfaces a distance at least equal to the dimension of the bosses and securing arms. The bosses and securing arms contact the edges of the opening to prevent a side-to-side rocking motion of the box within the opening of the wall.
U.S. Pat. No. 6,102,360 to Clegg et al. discloses a faceplate with fastening devices for securing a wall opening. The fastening devices have rearward projecting flanges and legs. The flanges locate the faceplate relative to the opening in the wall and the legs serve to limit rotation of the fastener as the fasteners are rotated to bring the arms into contact with the back side of the wall structure.
U.S. Pat. No. 6,093,890 to Gretz discloses a mounting device for a low voltage wall device for communication cables, television cables and fiber optics. The device has a frame with an integral reinforcing flange to fit within a rectangular hole formed in the wall. A pair of rotating flags are mounted on the ends of screws for grabbing the rear surface of the wall. The screws are tightened to mount the device securely to the wall.
Another device is shown in U.S. Pat. No. 5,603,424 to Bordwell. This device is attachable to a premanufactured electrical box to mount the box to a wall. A pair of clip-on securement members are mounted on each side wall of the box. The securement members include a bracket and a brace supported on the bracket. The brace is movable on the bracket to clamp the box to the wall.
The prior devices are generally effective for the intended use. There is, however, a continuing need in the industry for improved mounting devices that overcome the limitations of the prior devices.